Patent GB-854887-A (GB)
Title: A pipeline system and controls therefor
IPC: B65G53/30
Filed: 1958-01-02
Abstract: 854,887. Centrifugal pumps. PITTSBURGH CONSOLIDATION COAL CO. Jan. 2, 1958 [Jan. 17, 1957], No. 157/58. Class 110 (1). [Also in Groups XXIII, XXVIII and XXIX] Apparatus for conveying a coal-water slurry or liquid in an enclosed pipe line comprises a receiving station which pumps the liquid or slurry into the pipe line and one or more booster stations downstream of the pipe line. The receiving station 14 includes pumps 44, 46, 48, each driven by an electric motor through a fluid coupling, which pump the liquid or slurry from an inlet pipe 24 to a high-pressure accumulator 62 from there the liquid or slurry flows into the pipe line 70. When pumping a coal-water slurry, coal and water are fed into a slurry preparation tank 10 and through a pipe 12 to a storage tank 16 from there the slurry is pumped into the inlet pipe 24 by pumps 20, 22 and part of the slurry is recirculated into the storage tank 16 to prevent settling of the coal. The speed of the pumps 44, 46, 48 are normally controlled by the flow of liquid or slurry in the pipe line 70 adjacent the receiving station 14 through a flow measuring element 166 which transmits this rate of flow to a pressure controller 170 through conduit 168. The pressure controller in turn transmits a signal through conduit 171 to air motors 173 which regulate the amount of fluid in the couplings between the pumps and motors and thus the speed of the pumps. Normally one of the pumps serves as a standby while the other two are pumping. The high pressure accumulator 62 is provided with probes 174 and a liquid level indicator 176 so that the inert gas in the accumulator may be adjusted for normal flow conditions. If, in order to maintain the necessary flow required by measuring element 166, the pumps would need to be adjusted as above to exceed their normal working pressure, the pressure of the inert gas in accumulator 62 would rise and a signal is fed through conduit 172 to the controller 170, this signal overrides that from the flow measurer 166 and prevents the pumps exceeding their normal working pressure. When the required pressure to maintain the desired flow again falls the flow measurer 166 again becomes operative as above. Should the necessary feed to the pumps fall a pump 29 operates to feed liquid into the inlet pipe 24. The liquid or slurry flows through the pipe line 70 from the receiving station to a booster station 74 where the slurry flows into a low-pressure accumulator 80. The pumps 84, 86, 88 of the booster station operate in the same way as those of the receiving station except that they are normally controlled by the pressure of the liquid or slurry entering this station, the controller 154 receiving a signal through conduit 156 of the pressure of the inert gas in the low-pressure accumulator 80. The pumps feed the liquid or slurry to a high-pressure accumulator 108, provided with the overriding control as above, and the liquid or slurry flows back into the pipe line 70 and on to the next booster station and finally to the pipe line outlet or settling tank. Each station is provided with means for introducing corrosion and erosion inhibitor into the stream. Specifications 771,618 and 809,167 are referred to.